Furnace



(No Model.) 2 Sheets-Sheet 1. W. WALTERS.

FURNACE No. 479,771. Patented July 26, 1892.

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FURNACE. No. 479,771. Patgnted July 26, 1892.

@QQQ @909 UNITED STATES PATENT OFFICE,

WILLIAM WALTERS, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-FOURTH TO GEORGED. GARLAND, OF SAME PLACE.

FURNACE.

SPECIFICATION forming part of Letters Patent No. 479,771, dated July 26,1892.

Application filed October 20, 1891. Serial No. 409,275. (No model.)

To all whmn it may concern.-

Be it known that I, IVILLIAM WVALTERS, a citizen of the United States,residing in Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Furnaces, of whichthe'following is a specification.

My invention relates to steam-boiler furnaces and the acceleration ofcombustion therein, and more particularly in that class of steam-boilerfurnaces in which jets of combined air and steam are injected into thefirebox for promoting combustion.

The invention has for its primary object to provide improved means forretaining the smoke and other products of combustion not fully consumedwithin the furnace until perfect combustion has taken place, but withoutthereby retarding the free draft between the fire-chamber and theuptake, thereby obtaining the maximum degree of heat from'a given amountof fuel within a given period of time and preventing the discharge ofobjectionable products of combustion into the atmos phere.

My invention also has for its object to supply the combustion-chamber orfire-box with highly-combustible gas or vapor composed of heated air andsteam to assist in the thorough consumption of the partially-consumedproducts and to heat the said air by means of the heat of the fire-boxwithout thereby producing a detrimental and wasteful draft through thefuel, and at the same time to utilize such air for cooling thegrate-bars, and thus prevent them from burning out.

WVith these ends in view my invention consists in certain features ofnovelty by which the said objects and certain other objects of minorimportance are accomplished, hereinafter fully described, and moreparticularly pointed out in the claims.

In carrying out my invention I propose to retain the smoke andotherpartially consumed products of combustion within the tirebox untilperfect combustion has taken place by means of a current or currents ofcombustible gas, such as that resulting from combining highly-heated airand steam, which currents are directed across the fire-chamber in adownward direction toward the base of the bridge-wall, so that theascending products of combustion, instead of being permitted to rise andimmediately pass over the bridge-wall and thence into the uptake, aredepressed into contact with the incandescent fuel and compelled totraverse the Whole extent of the fire-box, during which time thecombined heat of the incandescent fuel and the burning stratum of gasthoroughly consumes them. This forced stratum of gas, while it has theeffect of retaining the smoke and unconsu med particles within thefire-box, it nevertheless does not retard the draft between the fire-boxand the uptake. It only prolongs the course or flight of the productswithin the fire-box and causes them all to pass to the hottest point inthe f urnacethat is, immediately in front of the bridge-wallbefore theycan ascend and pass over the latter; but by the time they reach thisPoint they are fully consumed, and hence the resulting heat only passesover the bridge -wall. In fact this forced stratum of gas, unlike theordinary buffer-draft, has a slight tendency to make the furnace drawmore freely, inasmuch as it is projected in the direction of the naturaldraft, it taking approximately the course indicated by the arrows inFig. 1that is, it

cuts across the fire-box to a point just in front of the bridge-wall,where its weakened velocity is overcome by the upward draft of theuptake and it is thereby deflected over the bridge-wall. The supply ofair necessary for the formation of this gas is drawn in through the firein the fire-box, but out of contact therewith, so as to be highlyheated, but without accelerating the draft through the fuel in passingthrough the latter, and the necessary steam is drawn from the steam- 9odome of the boiler or other suitable source, and the two are combinedand directed across the fire-chamber in the described manner, thedynamic force .of the steam being employed for drawing in the air andprojecting 5 the resultant gas in the desired direction.

In order that others skilled in the art may be able to make and use myinvention, the same will now be more particularly described withreference to the accompanying drawrco ings, in which Figure 1 is avertical longitudinal section of a steam-boiler furnace provided with myimprovements. Fig. 2 isa vertical transverse section taken on the lineII II, Fig. 1,looking in the direction of the arrows. Fig. 3 is a rearend elevation thereof. Fig. 4 is an enlarged detail sectional view ofone of the injector-nozzles hereinafter described. Fig. 5 is a plan viewof two of the grate-bars, and Fig. 6 is an end elevation of thegrate-bars hereinafter described.

In the drawings, wherein like signs of reference refer to like partsthroughout the several views, A is the furnace wall or setting, B aboiler arranged therein, 0 the combustion-chamber, D the ash-pit, E Fthe fire and ash doors, respectively, and G the bridgewall, all of theusual and well-known construction.

Supported on a flange or ledge H of the wall A is a manifold air-chamberI, which extends athwart the front part of the fire-box and is providedat suitable intervals, preferably at three places, as shown in Fig. 2,with upright or branch pipes K, whose upper extremities are providedwith injectors 7c, the nozzle ends L of which are flattened, as shown inFigs. 2 and 4, and aimed downwardly across the fire-chamber toward thebase of the bridge-wall, so as to project in such direction a flattenedstream or stratum of the fluid passing therethrough. The inner side ofthe transverse chamber I is preferably left open from end to end and itslower portion or bottom is provided with a slight extension h, uponwhich rest the ends of the grate-bars M. These grate-bars are hollowthroughout their extent and are preferably of approximately V shape, asshown in Fig. 2, but having square or rectangular portions m at bothends, which rest upon the flange H of the chamber I, and a cross beam orbar N at the inner side of the ash-pit, respectively. For the sake of amore perfect fit, each of the bars M is provided at both ends with aflange or lip O, which flanges rest in rabbeted portions 0 in the top ofthe chamber I and a supporting-plate P, secured in the inner wall of theash-pit, respectively, and the ends of the bars are so formed that whenthey are fitted together, as in Figs. 5 and 6, they will completely fillthe open side of the chamber 1 at their outer ends and form a continuouswall or partition, as shown in Fig. 6, at their inner ends.

The necessary steam to induce the inflow of air and form therewith thecombustible gas is drawn from the steam-dome Q or other suitable supplyand led m'a the pipe R, having regulating-valve S, to a manifold pipe T,which latter is provided with a number of branch pipes t, which leadinto the injectors 7c in a downward direction, as shown, and terminatewithin the nozzles L, so as to produce the requisite suction in thepipes K. The air is preferably drawn from the ash-pit, to which it issupplied through the doors F or other suitable draft-regulating device,and for this ma /t1 reason the grate-bars are made to fall short of theinner wall of the ash-pit or, in other words, such inner wall isinclined, as shown in Fig. 1, so as to form a chamber U at the rear orinner ends of the grate-bars, whereby the air entering through theash-doors F will be compelled to traverse the full length of the ash-pitand then enter the grate-bars at their inner ends, and thence traversesuch bars and empty into the chamber I, whence it ascends into the pipesK and is discharged through the nozzles L, as described.

By arranging the air-inlets to the injectors within the furnace in thismanner I not only obtain highly-heated air, but I prevent the greatnoise produced by the operation of the injector from being heard, afeature which has been found very objectionable withv air-injectorsdrawing their air immediately through a funnel located in the wall ofthe furnace. It will now be seen that the strong draft which is inducedby the injector does not pass upward through the grate-bars and into thefuel or affect the fire in any manner excepting that which has alreadybeen described, but the natural draft rises, as usual, from the ash-pitthrough the openings between the grate-bars and supports combustionbelow the stratum of gas projected across the fire-box withoutinterruption.

From the foregoing description it will be seen that the grate-bars areentirely independent of each other and do not require fastening devicesfor holding them in place, and hence maybe readily removed for cleaningthe furnace or putting in new bars by pushing the fire or fuel to oneside from overthe particular bar or bars to be replaced without dumpingthe fuel or materially affecting the operation of the device. For thesake of greater strength and rigidity, the grate-bars are provided atsuitable intervals with vertical ribs m, which come against each otherin the manner shown in Fig. 5, and thus prevent lateral as well asdownward bending.

The suction in the ash-pit D is so great that the apparatus may beutilized to advantage for ventilating the building in which it issituated; and when it is desired to do this the room or rooms to beventilated are connected to the ash-pit at the point 01 or othersuitable portion by means of any desirable and well-known system ofventilating-fines, the ash-doors in such case of course being keptclosed, so as to compel the draft to come through the ventilating-flues.

I prefer to utilize the grate-bars as a means for heating the air,because they are not only especially adapted for this purpose, but thecold air passing through them rapidly couducts away their heat andprevents them from burning out. WVhile I have described steam and air asa preferred form of gas for acting in the described manner to depressthe ascending products of combustion into contact with the incandescentfuel, I wish it to be understood that any other combustible gas IIOmight be used to the same end, or either steam or air alone might alsobe employed with good results.

Having described my invention, what I claim, and desire to secure byLetters Patent, 1s

1. In a furnace, the combination, with a fire-box and the ash-pit, ofthe injector-11ozzles arranged to direct a stratum vof fluid across thefire-box and hollow grate-bars communicating with the ash-pit at one endand with such injector-nozzles at their other ends, substantially as setforth.

2. In a furnace, the combination, with the fire-box and ash-pit, ofhollow grate-bars communicating with the ash-pit and an injectorarranged within the fire-box and having communication with saidgrate-bars and having its nozzle so aimed as to direct a current acrossthe fire-box in a downward direction, substantially as set forth.

3. In a furnace, the combination, with the fire-box and ash-pit, ofhollow grate-bars communicating with the ash-pit at their inner ends, amanifold chamber with which said bars communicate at their other ends,upright branch pipes leading from said manifold chamber, andinjector-nozzles on said branch pipes aimed across the firebox,subfire-box and ash-pit, of hollow grate-bars communicating with theash-pit at their inner ends, a manifold chamber with which said barscommunicate at their other ends, up-

right branch pipes leading from said mani fold chamber, andinjector-nozzles on said branch pipes aimed in a downwarddirectionacross the fire-box, so as to project fluid passing therethrough towardthe base of the bridge-wall, substantially as set forth.

5. In a furnace, the combination, with the fire-box and ash-pit,ofhollow independentlyremovable grate-bars having communication at theirinner ends with said ash-pit, a manifold chamber with which said barscoinmunt cate at their outer ends, branch pipes projecting upwardly fromsaid manifold chamber, and steam-injectors on the upper ends of saidpipes aimed toward the base of the bridgewall, substantially as setforth.

WILLIAM WALTERS. Witnesses:

F. A. HOPKINS, G. D. GARLAND.

